html,
body {
  width: 100%;
  height: 100%;
}
body {
  background-color: #f5f5f5;
  font: 14px/1.5 Helvetica, sans-serif, STHeiTi;
  color: #333;
  outline: 0;
}
img {
  vertical-align: bottom;
}
.fluid-img {
  width: 100%;
}
/*浮动工具类*/
.fl {
  float: left;
}
.fr {
  float: right;
}
/*清除浮动工具类*/
.clearfix::after {
  content: "";
  display: block;
  height: 0;
  visibility: hidden;
  clear: both;
}
.clearfix {
  *zoom: 1;
}
/*自定义居中混合*/
